docs: def registerApp(self,
                      itemId,
                      appType,
                      redirect_uris=None):
          """
          The register app operation registers an app item with the portal.
          App registration results in an APPID and APPSECRET (also known as
          client_id and client_secret (in OAuth speak respectively) being
          generated for that application. Upon successful registration, a
          Registered App type keyword gets appended to the app item.
  
          Inputs:
             itemId - The ID of item being registered. Note that the item
                      must be owned by the user invoking this operation
                      otherwise the call will be rejected.
  
             appType - The type of app that was registered indicating whether
                       it's a browser app, native app, server app or a
                       multiple interface app.
                       Values: browser | native | server| multiple
  
             redirect_uris - The URIs where the access_token or authorization
                             code will be delivered to upon successful
                             authorization. The redirect_uri specified during
                             authorization must be match one of the
                             registered URIs otherwise authorization will be
                             rejected.
                             A special value of urn:ietf:wg:oauth:2.0:oob can
                             also be specified for authorization grants. This
                             will result in the authorization code being
                             delivered to a portal URL (/oauth2/approval).
                             This value is typically used by applications
                             that don't have a web server or a custom URI
                             scheme to deliver the code to.
                             The value is a JSON string array.
          """
          url = self._url + "/registerApp"
          params = {
              "f" : "json",
              "itemId" : itemId,
              "appType" : appType
          }
          if redirect_uris is None:
              params['redirect_uris'] = redirect_uris
          return self._post(url=url,
                              param_dict=params,
                              securityHandler=self._securityHandler,
                              proxy_url=self._proxy_url,
                              proxy_port=self._proxy_port)